Supported carbon-containing molybdenum and tungsten sulfide catalysts, their preparation and use

ABSTRACT

A supported carbon-containing molybdenum sulfide and tungsten sulfide catalyst useful for conducting methanation and hydrotreating reactions, principally the latter, can be formed by compositing a preselected quantity of a porous, refractory inorganic oxide with a complex salt characterized by the formula 
     
         B.sub.x [MO.sub.y S.sub.4-y ] 
    
     where B is an organo or hydrocarbyl substituted diammonium ion, an organo or hydrocarbyl substituted ammonium ion or quaternary ammonium ion, or an ionic form of a cyclic amine containing one or more basic N atoms, x is 1 where B is an organo or hydrocarbyl substituted diammonium ion, or 2 where B is an organo or hydrocarbyl substituted ammonium or quaternary ammonium ion or an ionic form of a cyclic amine containing one or more basic N atoms, M is molybdenum or tungsten, and y is 0, or a fraction or whole number ranging up to 3, and heat decomposing the salt of said catalyst precursor composite in the presence of hydrogen sulfide and hydrogen to form said supported carbon-containing molybdenum sulfide or tungsten sulfide catalyst.

This is a division, of application Ser. No. 400,005 filed 7/20/82, nowU.S. Pat. No. 4,430,443.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

This invention relates to a process for the preparation of supportedcarbon-containing molybdenum and tungsten sulfide catalysts, thesupported catalyst species prepared by such process, and to the use ofsuch catalysts in methanation or hydrotreating. In particular, itrelates to a process for the preparation of a species of highly active,highly selective supported, metal-promoted hydrotreating catalysts, thecatalyst species prepared by such process, and the use of such catalystspecies in conducting methanation and hydrotreating processes,particularly the latter.

(2) Background and Prior Art

Hydrotreating processes are basic, and very well known to the petroleumrefining industry. These processes require the treating with hydrogen ofvarious hydrocarbon fractions, or whole heavy feeds, or feedstocks, inthe presence of hydrogenation (hydrogen transfer) catalysts to effectconversion of at least a portion of the feeds, or feedstocks to lowermolecular weight hydrocarbons, or to effect the removal of unwantedcomponents, or compounds, or their conversion to innocuous or lessundesirable compounds. Hydrotreating may be applied to a variety offeedstocks, e.g., solvents, light, middle, or heavy distillate feeds andresidual feeds, or fuels. In hydrofining relatively light feeds, thefeeds are treated with hydrogen, often to improve odor, color,stability, combustion characteristics, and the like. Unsaturatedhydrocarbons are hydrogenated, and saturated. Sulfur and nitrogen areremoved in such treatments. In the treatment of catalytic crackingfeedstocks, the cracking quality of the feedstock is improved by thehydrogenation. Carbon yield is reduced, and gasoline yield is generallyincreased. In the hydrodesulfurization of heavier feedstocks, orresiduas, the sulfur compounds are hydrogenated and cracked.Carbonsulfur bonds are broken, and the sulfur for the most part isconverted to hydrogen sulfide which is removed as a gas from theprocess. Hydrodenitrogenation, to some degree also generally accompanieshydrodesulfurization reactions. In the hydrodenitrogenation of heavierfeedstocks, or residuas, the nitrogen compounds are hydrogenated andcracked. Carbon-nitrogen bonds are broken, and the nitrogen is convertedto ammonia and evolved from the process. Hydrodesulfurization, to somedegree also generally accompanies hydrodenitrogenation reactions. In thehydrodesulfurization of relatively heavy feedstocks, emphasis is on theremoval of sulfur from the feedstock which is usually converted to lowermolecular weight, or lower boiling components. In thehydrodenitrogenation of relatively heavy feedstocks emphasis is on theremoval of nitrogen from the feedstock, which also is converted to lowermolecular weight, or lower boiling components. Albeit,hydrodesulfurization and hydrodenitrogenation reactions generally occurtogether, it is usually far more difficult to achieve effectivehydrodenitrogenation of feedstocks than hydrodesulfurization offeedstocks.

The dwindling supplies of high grade petroleum feedstocks necessitatesthe increased production and processing of transportation fuels fromlower grade, heavy petroleum feedstocks and synthetic liquidhydrocarbons derived from hydrocarbon-containing, or precursorhydrocarbon-containing, solids. The refiners' feedstock sources as aresult thereof continue to change, particularly as the worldwidesupplies of petroleum diminish. The newer feedstocks often containhigher amounts of nitrogen, sulfur, and other materials. Nonetheless,whatever the difficulties, it remains a necessity to effectivelyhydrotreat the new feedstocks; often to a greater extent than previouslywas required. It has thus become necessary to process whole heavypetroleum crudes and residua from unconventional sources, as well assynthetic fuels (syncrudes; e.g. liquified coal, oil from coalcarbonization, oil from tar sands, shale oil and the like inclusive ofresidua or viscous syncrude fractions). All, particularly the later, areunder active consideration as commercial feedstocks, or feedstockreplacements for higher grade petroleum sources. Feedstocks derived fromthese sources are often of high olefinic content, contain more sulfur ornitrogen, or both, than feedstocks derived from more conventional crudeoils.

Naphthas, notably those derived from syncrudes, viz. residua, shale oil,and coal, are highly unsaturated and contain considerably more sulfur,nitrogen, olefins, and condensed ring compounds than the moreconventional naphthas. For example, nitrogen and sulfur are contained incat naphtha in concentrations ranging upwardly from 50 ppm and 1000 ppm,respectively. In coal liquids nitrogen and sulfur are present inconcentrations ranging upwardly from 1300 ppm and 5000 ppm,respectively; and oxygen is presently in even higher concentrations.These compounds cause activity suppression and an all too rapiddeactivation of the catalysts. Coke formation is increased, and there ismore cracking with increased gas production. Albeit these compounds,except for condensed ring naphthenic compounds, can be removed byconventional hydrofining, this is a severe, if not an intolerableprocess burden due to the large hydrogen consumption; and hydrogenbecomes more and more a very expensive commodity. Thus, generallyconsiderably more upgrading is required to obtain usable products fromthese sources. Such upgrading generally necessitates hydrotreating thevarious hydrocarbon fractions, or whole crudes, and includes reactionssuch as hydrogenating to saturate olefins and aromatics,hydrodesulfurizing to remove sulfur compounds, hydrodenitrogenating toremove nitrogen, and conversion of high boiling compounds to lowerboiling compounds.

Typical hydrotreating catalysts are exemplified by cobalt molybdate onalumina, nickel molybdate on alumina, cobalt molybdate promoted withnickel, and the like. Certain transition metal sulfides such as cobaltand molybdenum sulfides and mixtures thereof have also been employed inhydrofining processes for upgrading oils which contain sulfur andnitrogen compounds. For example, U.S. Pat. No. 2,914,462 discloses theuse of molybdenum sulfide for hydrodesulfurizing gas oil and U.S. Pat.No. 3,148,135 discloses the use of molydenum sulfide for hydrorefiningsulfur and nitrogen-containing hydrocarbon oils. U.S. Pat. No. 2,715,603discloses the use of molybdenum sulfide as a catalyst for thehydrogenation of heavy oils, while U.S. Pat. No. 3,074,783 discloses theuse of molybdenum sulfides for producing sulfur-free hydrogen and carbondioxide, wherein the molybdenum sulfide converts carbonyl sulfide tohydrogen sulfide. A serious disadvantage associated with the use of suchcatalysts is their relatively high cost, and the supply of catalyticmetals is rather limited. Moreover, the reaction rates of such catalystsare relatively slow, particularly in the presence of nitrogen; andhydrogen consumption is quite high. These latter problems areparticularly oppressive when it is realized that new generation feedsare unusually high in nitrogen, or sulfur, or both, and the cost ofhydrogen is increasing at very high rates.

Molybdenum sulfide is also known to be useful for water gas shift andmethanation reactions, as well as for catalyzed hydrotreatingoperations. Recently, e.g., it was disclosed in U.S. Pat. Nos. 4,243,553and 4,243,554 that molybdenum disulfide catalysts of relatively highsurface area can be obtained by thermally decomposing selectedthiomolybdate salts at temperatures ranging from 300°-800° C. in thepresence of essentially inert, oxygen-free atmospheres, e.g.,atmospheres of reduced pressure, or atmospheres consisting of argon,nitrogen, and hydrogen, or mixtues thereof. In accordance with theformer, a substituted ammonium thiomolybdate salt is thermallydecomposed at a very slow heating rate of from about 0.5 to 2° C./min,and in accordance with the latter an ammonium thiomolybdate salt isdecomposed at a rate in excess of 15° C. per minute to form the highsulface area molybdenum disulfide.

There remains a need in the art for new, improved hydrotreatingcatalysts, especially hydrotreating catalysts which are more highlyactive, selective, and stable.

It is accordingly a primary objective of the present invention toprovide this need, particularly by providing new and improvedhydrotreating catalysts, a process for the preparation of thesecatalysts, and process for the use of these catalysts in conductinghydrotreating reactions.

A particular object is to provide novel hydrogen efficient hydrotreatingcatalysts which are especially active for the hydrodesulfurization, orhydrodenitrogenation, or both, of hydrocarbon feedstocks which containrelatively high concentrations of sulfur, or nitrogen, or both; as wellas a process for the use of such catalysts in conducting such reactions.

A further, and more particular object is to provide novel hydrotreatingcatalysts of such character which are highly selective for conductinghydrodesulfurization, or hydrodenitrogenation reactions, or both; aswell as a process for the use of such catalysts in conducting suchreactions.

A yet further, and more specific object is to provide novel methanationcatalysts, a process for the preparation of such catalysts, and aprocess for the use of such catalysts in conducting methanationreactions.

BRIEF DESCRIPTION OF THE FIGURE

The FIGURE is a plot of hydrogen consumption vs. Product nitrogenresulting in the hydrotreatment of Baton Rouge Light Catalytic CycleOil.

DESCRIPTION OF THE INVENTION

These and other objects are achieved in accordance with the presentinvention embodying catalysts, and process for producing such supportedcarbon-containing molybdenum and tungsten sulfide hydrotreatingcatalysts, both promoted and unpromoted species, which have admirablyhigh activity, selectivity, and stability especially in conductinghydrodesulfurization and hydrodenitrogenation reactions at high levelsof hydrogen efficiency with various sulfur and nitrogen containinghydrocarbon feeds. In accordance therewith, a supportedcarbon-containing molybdenum sulfide and tungsten sulfide hydrotreatingcatalyst is formed by compositing a preselected quantity of a porous,refractory inorganic oxide with a complex salt characterized by theformula

    B.sub.x [MO.sub.y S.sub.4-y ]

where B is an organo or hydrocarbyl substituted diammonium ion, anorgano or hydrocarbyl substituted ammonium ion or quaternary ammoniumion, or an ionic form of a cyclic amine containing one or more basic Natoms, x is 1 where B is an organo or hydrocarbyl substituted diammoniumion, or 2 where B is an organo or hydrocarbyl substituted ammonium orquaternary ammonium ion or an ionic form of a cyclic amine containingone or more basic N atoms, M is molybdenum or tungsten, and y is 0, or afraction or whole number ranging up to 3, and heat decomposing the saltof said catalyst precursor composite in the presence of hydrogen andhydrogen sulfide to form said supported carbon-containing molybdenumsulfide or tungsten sulfide hydrotreating catalyst. Suitably, a solutionof the salt, or admixture of salts, is incorporated with a preselectedquantity of a porous, refractory inorganic oxide support, preferably aparticulate mass of said support, the salt-containing support thenpreferably dried to remove all or a portion of the solvent from thesupport, and the dried particulate salt-containing support then heatedin the presence of hydrogen and hydrogen sulfide to the decompositiontemperature of said salt, or salts, to form the catalyst species of thisinvention. Suitably, sufficient of the salt, or salts, is incorporatedon the support so that prior to, or at the time the salt, or salts, isdecomposed from about 5 percent to about 30 percent, preferably fromabout 10 percent to about 25 percent of the salt, expressed as weightMoO₃ or WO₃ on an ignition loss free basis, will be present on thesupport. The supported catalyst species is stable, highly active andselective as a hydrotreating catalyst. The hydrotreating capacity ofsuch catalysts in a preferred embodiment can be further promoted, andtransformed into a yet more effective hydrotreating catalyst by thefurther incorporation therewith of a Group VIII metal or admixture ofsuch metals, of the Periodic Table of the Elements (E. H. Sargent & Co.,Copyright 1962, Dyne-Slide Co.).

The precise nature, and composition of the catalyst species that isformed as a reaction product of the decomposition reaction is not known,but it is believed that a catalyst species having the general formulaMS_(2-z) C_(z'), wherein M is molybdenum or tungsten, and z and z' arethe same or different and range from about 0.01 to about 0.5, is formed,and supported upon the porous, refractory inorganic oxide base. Thesurface composition, or composition deposited on the surface of thesupport, is thus believed to correspond generally with the unsupportedcatalyst species defined in Application Ser. Nos. 399,999 and 399,991,each jointly filed by Theresa R. Pecoraro and Russel R. Chianelli, andRussel R. Chianelli and Theresa R. Pecoraro, respectively, filed Nov.14, 1983, both abandoned; the disclosures of which are herewithincorporated by reference.

The catalyst species of Pecoraro and Chianelli are, like those ofApplicants, defined as carbon-containing molybdenum and tungstensulfides, useful for hydrorefining hydrocarbon feedstocks, and thesebasic materials can be promoted with transition metal sulfides such ascobalt sulfide. These catalyst species are preformed, or formed in-situ,by contacting a hydrocarbon feed at elevated temperature with one ormore catalyst precursors selected from the group consisting of (a)ammonium thiomolybdate or thiotungstate salts, (b) ammonium molybdate ortungstate salts, (c) substituted ammonium thiomolybdate or thiotungstatesalts, (d) substituted ammonium molybdate or tungstate salts, andmixtures thereof. Unlike Applicants' catalyst species, however, thecatalyst species of Pecoraro and Chianelli are unsupported, bulkcatalysts. They thus differ from the supported carbon-containingmolybdenum and tungsten catalyst species defined herein; and differsubstantially, inter alia, in that the catalyst species of the presentinvention achieves superior utilization of the catalytic metals presenton the catalyst, and better hydrogen utilization.

A starting material for use in the preparation of the catalyst of thisinvention can, as suggested, be characterized as an organo orhydrocarbyl diammonium ion substituted, an ammonium or quaternaryammonium ion substituted, or an ionic form of a basic cyclic aminesubstituted thiomolybdate, or thiotungstate, salt having the formulaB_(x) [MO_(y) S_(4-y) ], supra. In such formula B is thus an organo orhydrocarbyl substituted diammonium ion, an organo or hydrocarbylsubstituted ammonium ion or quaternary ammonium ion, or an ionic form ofa cyclic amine containing one or more basic N atoms, x is 1 where B isan organo or hydrocarbyl substituted diammonium ion, or 2 where B is asubstituted ammonium or quaternary ammonium ion, or an ionic form of acyclic amine containing one or more basic N atoms, M is molybdenum ortungsten, preferably molybdenum, and y is 0, or a fraction or wholenumber ranging up to 3. Preferably y ranges from 0 to 0.5. In theformula the B moiety, or moieties, constitutes a cationic entity, orentities, which forms a complex with an anionic [MO_(y) S_(4-y) ]²⁻moiety. An organo, or hydrocarbyl diammonium ion moiety thus providestwo positive charges in formation of a B_(x) [MO_(y) S_(4-y) ] salt. Onthe other hand, two of the substituted ammonium or quaternary ammoniumions, or anionic form of a cyclic amine which contains one or more basicN atoms complex with an anionic [MO_(y) S_(4-y) ]²⁻ moiety. Thesubstituent amino groups of the organo, substituted diammonium ion, orsubstituted ammonium ion, where B is a substituted diammonium ion orsubstituted ammonium ion, can be characterized as primary, secondary ortertiary, in that the hydrogen atoms of one or both of the substituentamino groups of B can be substituted or unsubstituted as with an organo,a hydrocarbyl radical or hydrocarbon radical selected from the groupconsisting of alkyl, aralkyl, cycloalkyl, aryl, alkaryl, alkenyl, andalkynyl, preferably alkyl or aryl, and including such radicals wheninertly substituted. Such radical can thus be exemplified by hydrocarbongroups which contain from about one to about 30 carbon atoms, preferablyfrom about one to about 20 carbon atoms. When the hydrocarbyl, orhydrocarbon radical is alkyl, it can typically be methyl, ethyl,n-propyl, iso-propyl, n-butyl, i-butyl, sec-butyl, amyl, octyl, decyl,octadecyl, and the like. When it is aralkyl it can typically be benzyl,betaphenylethyl, and the like. When it is cycloalkyl, it can typicallybe cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl,2-methyl-cycloheptyl, 3-butyl cyclohexyl, 3-methyl cyclohexyl, and thelike. When it is aryl, it can typically be phenyl, ethylphenyl, and thelike. When alkaryl, it can typically be tolyl, xylyl, and the like. Whenalkenyl, it can typically be vinyl, allyl, 1-butenyl, and the like. Whenit is alkynyl, it can typically be ethynyl, propynyl, butynyl, and thelike. The hydrocarbyl, or hydrocarbon radical can be inertlysubstituted, i.e., it may bear a non-reactive substitutent such asalkyl, aryl, cycloalkyl, ether, halogen, nitro, and the like. Typicallyinertly substituted groups may include 3-chloropropyl, 2-ethoxyethyl,4-methyl cyclohexyl, p-chlorophenyl, p-chloro benzyl,3-chloro-5-methylphenyl, and the like.

Exemplary of B, i.e., where B is a diammonium ion substitutient of suchsalts, are the ionic forms of aliphatic diamines; e.g., alkyl diaminessuch as those derived from straight chain hydrocarbons which contain anamino group on two different carbon atoms, as on each terminal carbonatom, i.e., H₂ N(CH₂)_(n) NH₂, where n ranges from 1 to about 30,preferably from 1 to about 20, illustrative of which are methyldiamines, ethylene diamines, n-propyl diamines, hexyl diamines, decyldiamines, dodecyl diamine, and the like, and including aliphaticdiamines which contain amino groups on adjacent carbon atoms such as 1,2bis(amino)-n-butane, or those which contain amino groups on separatedcarbon atoms such as 1,3 bis(amino)-n-butane, or the like; cyclicdiamines, e.g., aromatic diamines, such as those which contain twoprimary amino groups attached to a fused or non-fused ring structure,e.g., p-diamino benzene, phloroglucinol, o-diamino naphthalene,p-phenylene-diamines, and the like. Suitable salts formed from suchsubstitutients are thus exemplified by

[H₃ NC₃ H₆ NH₃ ][MoO₀.5 S₃.5 ];

[H₃ NC₆ H₁₂ NH₃ ][MoO₀.3 S₃.7 ];

[H₃ NC₈ H₁₆ NH₃ ][WO₀.5 S₃.5 ];

[CH₃ CHNH₃ CHNH₃ C₂ H₅ ][MoO₀.4 S₃.6 ];

[CH₃ CHNH₃ CH₂ CHNH₃ C₃ H₇ ][MoO₀.5 S₃.5 ];

[CH₂ CHNH₃ CH₂ CHNH₃ C₃ H₇ ][MoS₄ ];

and the like.

The B moieties of the substituted ammonium thiomolybdate, orthiotungstate salt can, as suggested, also be constituted of ammoniumions wherein one or more of the hydrogen atoms of the ions have beenreplaced by an organo, hydrocarbyl or hydrocarbon radical, selected fromthe group consisting of alkyl, aralkyl, cycloalkyl, aryl, alkaryl,alkenyl and alkynyl, including such radicals when inertly substituted.The hydrocarbon moiety is exemplified by hydrocarbon groups whichcontain from 1 to about 30 carbon atoms, preferably from about one toabout 20 carbon atoms. Exemplary of substitutients associated with, orsubstituted upon the ammonium or quaternary ammonium ion to form each ofthe two B constituents of the salt are, when the substituent is alkyl,methyl, ethyl, n-propyl, iso-propyl, n-butyl, i-butyl, sec-butyl, amyl,octyl, decyl, octadecyl, and the like; when the substituent is aralkyl,benzyl, betaphenylethyl, and the like; when the substituent iscycloalkyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl,2-methylcycloheptyl, 3-butyl cyclohexyl, 3-methyl cyclohexyl, and thelike; when the substituent is aryl, phenyl, ethylphenyl, and the like;when the substituent is alkaryl, tolyl, xylyl, and the like; when thesubstituent is alkenyl, vinyl, allyl, 1-butenyl, and the like; when thesubstituent is alkynyl, ethynyl, propynyl, butynyl, and the like. Thesubstituent, as suggested, can be inertly substituted, i.e., it may beara non-reactive substitutent such as alkyl, aryl, cycloalkyl, ether,halogen, nitro, and the like. Typically inertly substituted groups mayinclude 3-chloropropyl, 2-ethoxyethyl, 4-methyl cyclohexyl,p-chlorophenyl, p-chloro benzyl, 3-chloro-5-methylphenyl, etc.Substituted ammonium ions of such types are thus those containing oneorgano or hydrocarbyl group, e.g., n-C₄ H₉ NH₃ ⁺, C₆ H₅ NH₃ ⁺, and thelike, those containing two organo or hydrocarbyl groups, e.g., (C₂ H₅)₂NH₂ ⁺, (C₆ H₅)₂ NH₂ ⁺, and the like, those containing three organo orhydrocarbyl groups, e.g., n-(C₆ H₁₃)₃ NH⁺, (C₆ H₅)₃ NH⁺, and the like;and those containing four organo or hydrocarbyl groups, e.g., (C₆ H₅CH₂)₄ N⁺, (C₆ H₅)₄ N⁺, and the like. Suitable salts useful in thepractice of this invention are thus exemplified by

H₃ NC₆ H₄ NH₃ [MoO₀.2 S₃.8 ];

[(C₂ H₅)NH₃ ⁺ ]₂ [MoO₀.4 S₃.6 ];

[(C₆ H₅)₂ NH₂ ⁺ ]₂ [MoO₀.4 S₃.6 ];

[(C₆ H₅)₂ NH₂ ⁺ ]₂ [MoO₀.1 S₃.9 ];

[(C₆ H₁₃)₃ NH⁺ ]₂ [MoO₀.2 S₃.8 ];

[(C₆ H₅)₄ N⁺ ]₂ [MoO₀.1 S₃.9 ];

[(C₆ H₁₃)₄ N⁺ ]₂ [MoS₄ ]; [(C₆ H₅)₄ N⁺ ]₂ [WS₄ ];

and the like.

The B moieties of the catalyst precursor salt can, as suggested, also beconstituted of an ionic form of a cyclic amine which contains one ormore basic nitrogen atoms within the ring, generally from one to aboutthree basic atoms in the total molecule. This class of compounds can beconstituted of rings having 5, 6, or more members, and can be monocyclicor polycyclic, fused or non-fused rings, non-substituted or inertlysubstituted, which contain from one to about 3 basic nitrogen atoms inthe total molecule. Exemplary of ionic forms of cyclic amines of thischaracter are the ionic forms of such monocyclic five membered rings aspyrrole, isopyrrole, pyrazole, 2-isoimidazole, 1,2,3-triazole and thelike; such monocyclic six membered rings as pyridine, pyridazine,pyrimidine, pyrazine, s-triazine and the like; and such fused ring,polyclic structures as indole, 1,5-pyrindine, quinoline, naphthyridine,purine, acridine and the like. Suitable salts useful in the practice ofthis invention are thus exemplified by

[C₅ H₅ NH]₂ [MoO₀.5 S₃.5 ]; [C₄ H₄ N₂ H]₂ [MoO₀.5 S₃.5 ];

[C₄ H₄ N₂ H]₂ [WO₀.4 S₃.6 ]; [C₃ H₃ N₃ H]₂ [MoO₀.2 S₃.8 ];

[C₈ H₈ N₂ H]₂ [MoO₀.4 S₃.6 ]; [C₁₃ H₁₃ NH]₂ [MoS₄ ]

and the like.

The organo or hydrocarbyl diammonium ion substituted, ammonium orquaternary ammonium ion substituted, or ionic form of a basic cyclicamine substituted thiomolybdate, or thiotungstate, salt is preferablyimpregnated upon a porous, refractory, inorganic oxide support, suitablyby first dispersing or dissolving said salt, or admixture of salts, in asuitable solvent, and then admixing or slurrying a preselected amount ofthe precursor thiomolybdate, or thiotungstate, salt solution with apreselected quantity of said support material in particulate form.Virtually, any solvent can be employed which is capable of dissolvingthe precursor thiomolybdate or thiotungstate salt, without adverselyreacting therewith. Albeit, an aqueous solvent can be employed, nonaqueous solvents are preferred because few of the organo or hydrocarbyldiammonium ion substituted, ammonium or quaternary ammonium ionsubstituted, or ionic form of basic cyclic amine substitutedthiomolybdate, or thiotungstate, salts are adequately soluble in water.Suitable solvents for dissolving these salts are alcohols, ethers,ketones, paraffins, cycloparaffins and aromatic hydrocarbons, exemplaryof which are methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropylalcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, t-butylalcohol, ethyl ether, tetrahydrofuran, acetone, methyl ethyl ketone,hexane, heptane, cyclobutane, aromatic hydrocarbons, notably thosehaving a single benzene nucleus, especially aromatic hydrocarbonscontaining from about 6 to about 9 carbon atoms, e.g., benzene, toluene,xylene, n-propyl benzene, isopropyl benzene, and the like; andcycloparaffin hydrocarbons which contain from about 4 to about 9 carbonatoms, e.g., cyclobutane, cyclopentane, cyclohexane, cycloheptane, andthe like. Preferred solvents are alcohols, especially the low molecularweight simple alcohols, e.g., methyl alcohol, ethyl alcohol and thelike; amines, e.g., butyl amine, ethylenediamine and the like; andketones, e.g., acetone, methylethyl ketone, and the like.

The organo or hydrocarbyl diammonium ion substituted, ammonium orquanternary ammonium ion substituted, or ionic form of a basic cyclicamine substituted thiomolybdate, or thiotungstate, salt is composited orotherwise intimately associated with the porous, inorganic oxide supportby various techniques known to the art, such as coprecipitation,impregnation or the like. The composite is preferably formed from asolution of the desired salt, or salts by impregnation of the support,typically via an "incipient wetness" technique which requires a minimumof solution so that the total solution with the preselected desiredamount of the catalyst precursor salt is adsorbed, initially or aftersome evaporation. Typically, a particulate porous refractory inorganicoxide, notably alumina, in the form of beads, pills, pellets, seivedparticles, extrudates, or the like in dry or solvated state is contactedwith a solution of the salt, or admixture of the salts, with the resultthat the salt solution is adsorbed into the particulate material in thedesired amount. The salt-containing particulate material can thereafterbe heated and dried at low temperature, with or without vacuumassistance, e.g., at temperatures ranging at or below the boilingtemperature of the solvent.

The preferred support is alumina, and the composite support can containfor example, one or more of alumina, bentonite, clay, diatomaceousearth, zeolite, silica, activated carbon, magnesia, zirconia, thoria,titania and the like, these latter with alumina, usually in a range ofabout 1 to 20 percent, based on the weight of the support. A preferredsupport for the practice of the present invention is one having asurface area of more than 50 m² /g, preferably from about 100 to about300 m² /g, a bulk density of about 0.3 to 1.0 g/ml, preferably about 0.4to 0.8 g/ml, an average pore volume of about 0.2 to 1.1 ml/g, preferablyabout 0.3 to 0.8 ml/g, and an average pore diameter of about 30 to 300Å.

The catalyst precursor material, or material formed by impregnation ofthe support with the organo or hydrocarbyl diammonium ion substituted,substituted ammonium or quaternary ammonium ion, or ionic form of abasic cyclic amine salt is preferably dried to remove all or a portionof the solvent, but it is never calcined after the salt is added to thesupport. The support is preferably dried at a temperature below about100° C., more preferably between about 50° C. and 80° C., in thepresence of nitrogen or oxygen, or both, at static or dynamicconditions, in air or under vacuum. The catalyst precursor material, ona dry basis, contains from about 5 percent to about 30 percent,preferably from about 10 percent to about 25 percent of the undecomposedorgano or hydrocarbyl diammonium ion substituted, ammonium or quaternaryammonium ion substituted, or ionic form of a basic cyclic aminesubstituted thiomolybdate, or thiotungstate, salt, expressed as weightMoO₃ or WO₃ on an ignition loss free basis.

The catalyst precursor is heated to the decomposition temperature of theimpregnating salt, and the salt decomposed in the presence of hydrogen,and hydrogen sulfide, to form the supported catalyst species of thisinvention. The hydrogen required for forming the catalysts of thisinvention may be pure hydrogen, an admixture of gases rich in hydrogenor a compound which will generate in situ hydrogen, e.g., ahydrogen-bearing gas such as hydrogen sulfide, or a hydrogen donorsolvent. The hydrogen sulfide can likewise be added as an essentiallypure gas, as a gas which contains hydrogen sulfide; or the hydrogensulfide can be generated in situ from a sulfur-containing compound,e.g., a sulfur dioxide, carbon disulfide or thiocarbamide. Suitably, thecatalyst precursor composition is heated, and the salt portion thereofdecomposed in a hydrogen atmosphere which contains from about 0.5percent to about 50 percent, preferably from about 5 percent to about 20percent hydrogen sulfide, based on the total volume of gas.

In decomposing the catalyst precursor, a bed of the dried catalystprecursor is contacted in a hydrogen sulfide/hydrogen atmosphere andheated at conditions which decompose the diammonium ion substituted,ammonium or quaternary ammonium ion substituted, or ionic form of abasic cyclic amine substituted thiomolybdate, or thiotungstate, saltcomponent of said catalyst precursor. For example, a fixed bed of thedried catalyst precursor is charged into a reaction vessel and contactedwith the gaseous hydrogen sulfide/hydrogen admixture at temperaturesufficient to thermally decompose the salt portion of the catalystprecursor composite, such temperature generally ranging from about 150°C. to about 400° C., or more often from about 200° C. to about 370° C.,a flow rate of hydrogen sulfide/hydrogen ranging from about 50 to about5000 V/H/V, preferably from about 100 to about 1000 V/H/V, and atpressures ranging from about 0 to about 2000 pounds per square inchgauge (psig), preferably 0 to about 200 psig. Thereafter the feedhydrocarbon, or admixture of liquid hydrocarbons, can be introduced toinitiate the hydrotreating operation, the feed being introducedgenerally at a flow rate of hydrocarbon:catalyst at from about 0.05 toabout 50, preferably from about 0.1 to about 10, volumes of hydrocarbonper volume of catalyst per hour, a flow rate of hydrogen ranging fromabout 250 to about 5000 SCF/B, preferably from about 500 SCF to about3000 SCF/B, and at pressures ranging from about 50 to about 4000 psig,preferably from about 150 to about 2500 psig. Typically the hydrocarbonis introduced downflow, but can be introduced upflow or downflow overthe bed of catalyst. The temperature of the reaction if necessary afterformation of the catalyst is gradually raised after the decompositiontemperature of the organo or hydrocarbyl diammonium ion substituted,ammonium or quaternary ammonium ion substituted, or ionic form of abasic cyclic amine substituted thiomolybdate, or thiotungstate, saltcomponent is reached.

In the preparation of the catalysts of this invention, the salts of thecatalyst precursor composite are decomposed in an atmosphere of hydrogensulfide and hydrogen at temperatures ranging between about 150° C. and400° C., and more generally between about 200° C. and 370° C. whichtemperatures correspond generally with, or are exceeded by hydrotreatingtemperatures. Where, however, the decomposition temperature of thecatalyst precursor is lower than the desired hydrotreating temperature,the temperature in conducting the hydrotreating process is raised tothat which is desired for conducting the hydrotreating operation. In atypical operation, sulfiding conditions are provided, and thetemperature is gradually raised to the decomposition temperature of thecatalyst precursor, the catalyst precursor is decomposed in the presenceof the hydrogen sulfide and hydrogen to form the catalytically activespecies, and the temperature then further increased as desired toconduct the hydrotreating operation. Hydrotreating conditions varyconsiderably depending on the nature of the hydrocarbon beinghydrogenated, the nature of the impurities or contaminants to be reactedor removed, and, inter alia, the extent of conversion desired, if any.In general however, the following are typical conditions forhydrotreating a naphtha boiling within a range of from about 25° C. toabout 210° C., a diesel fuel boiling within a range of from about 170°C. to 350° C., a heavy gas oil boiling within a range of from about 325°C. to about 475° C., or residuum containing from about 10 percent toabout 50 percent of a material boiling above about 575° C.

    ______________________________________                                                                       Space  Hydrogen                                              Temp.,   Pressure                                                                              Velocity                                                                             Gas Rate                                Feed          °C.                                                                             psig    V/V/Hr SCF/B                                   ______________________________________                                        Naptha                                                                              Typi-   100-370  150-800 0.5-10  100-2000                                     cal                                                                           Pre-    150-260  250-400 2-6     500-1500                                     ferred                                                                  Diesel                                                                              Typi-   200-400   250-1500                                                                             0.5-4   500-6000                                     cal                                                                     Fuel  Pre-    260-340   00-1000                                                                              1-2    1000-2000                                     ferred                                                                  Heavy Typi-   160-430   250-2500                                                                             0.3-2  1000-6000                                     cal                                                                     Gas   Pre-    320-385   600-1250                                                                             0.5-1  1500-4000                               Oil   ferred                                                                  Resi- Typi-   340-450  1000-5000                                                                             0.1-1    2000-10,000                           duum  cal                                                                           Pre-    360-400  1250-2000                                                                             0.25-0.5                                                                             4000-6000                                     ferred                                                                  ______________________________________                                    

The catalyst of this invention can be promoted to further dramaticallyincrease the activity of the finished catalyst by the further additionof a Group VIII metal of the Periodic Table of the Elements (E. H.Sargent & Co., Copyright 1962, Dyna-Slide Co.), which metal can be addedto the refractory porous inorganic oxide, or alumina, support prior to,simultaneously with, or subsequent to the decomposition of the organo orhydrocarbyl diammonium ion substituted, ammonium or quaternary ammoniumion substituted, or ionic form of a basic cyclic amine substitutedthiomolybdate, or thiotungstate, salt on treatment of the catalystprecursor in the presence of hydrogen sulfide and hydrogen. Suitablysuch metal promoter, or metal promoters, particularly iron, cobalt andnickel, alone or in admixture one metal with another, is incorporatedwith the support, notably alumina, as via cogellation or impregnationprior to incorporation of the organo or hydrocarbyl diammonium ionsubstituted, ammonium or quaternary ammonium ion substituted, or ionicform of a basic cyclic amine substituted thiomolybdate, orthiotungstate, salt with the dried, calcined support. Preferably, themetal promoter, or metal promoters, is added to the catalyst after theorgano or hydrocarbyl diammonium ion substituted, ammonium or quaternaryammonium ion substituted, or ionic form of a basic cyclic aminesubstituted thiomolybdate, or thiotungstate, salt impregnated upon thesupport has been treated, and decomposed.

The Group VIII metal components, admixed one component with another orwith a third or greater number of metal components, can be composited orintimately associated with the porous inorganic oxide support byimpregnation of the support with metals, e.g., with the alumina, by an"incipient wetness" technique, or technique wherein a metal, or metalsis contained in a solution, preferably water or alcohol, in measuredamount and the entire solution is absorbed into the support andsubsequently dried, and calcined if desired, to form the catalyst. Thevolume amount of solution to be employed in such recipe is separatelydetermined by measuring the amount of solvent required to wet a knownweight of support to the point where some liquid bridging betweenparticles or some miniscus formation between particles and containerwalls just becomes evident. This ratio of volume of solution to weightof support is then used proportionally to calculate the volume ofsolution containing catalytic metals to be used in the incipient wetnessimpregnation. Impregnation by adsorption of the metals from dilutesolution onto the support can also be used but this method is moreappropriate for low concentrations, e.g., from about 0.01 to about 1.0percent of catalytic metals desired, and it is less preferable for usein the higher metals concentration ranges. The metal impregnatedsupport, after impregnation, is dried, e.g., at temperatures rangingfrom about 20° C. to about 150° C., preferably at ambient temperatures,e.g., from about 20° to about 30° C., until free flowing and then fromabout 80° C. to about 110° C. as in a circulating air, vacuum oven,microwave oven, or the like.

The following examples, with comparative demonstrations, are furtherexemplary of the highly active, highly selective catalysts of thisinvention for use in hydrotreating, especially hydrodesulfurization(HDS) or hydrodenitrogenation (HDN), or both. In the examples anddemonstrations which follow, all parts are in terms of weight units,pressures in terms of pounds per square inch gauge, temperatures areexpressed in terms of degrees Centigrade, gas flow rates in terms ofSCF/Bbl, and liquid flow rates in terms of LHSV except as otherwisespecified.

EXAMPLE 1

This example demonstrates the advantages of catalysts prepared by theprocess of this invention, i.e., by decomposing the supported complexsalt, B_(x) [MO_(y) S_(4-y) ], in the presence of hydrogen sulfide andhydrogen to produce a catalyst of high hydrodenitrogenation activity,and acceptable hydrodesulfurization activity. The hydrodenitrogenationand hydrodesulfurization activity of this catalyst is compared with oneproduced according to the method disclosed and claimed in our copendingApplication Ser. No. 400,004 filed July 20, 1982 now U.S. Pat. No.4,431,747 which issued Feb. 14, 1984, and with a commercially availablehydrodesulfurization catalyst.

A solution was prepared by dissolving 38.628 g of tetrabutylammoniumthiomolybdate in enough methanol to give 80 ml of solution. Analysis ofthe tetrabutylammonium thiomolybdate indicated that it had theapproximate formula ((C₄ H₉)₄ N)₂ (MoO₀.2 S₃.8).1.7H₂ O. A 50 ml portionof this solution was used to impregnate to incipient wetness 50 g ofgamma alumina, which had 265.7 m² /g surface area and 0.750 ml/g porevolume, and which had been ground and screened to 14/35 Tyler mesh andcalcined 4 hours at 540° C. before impregnation. The alumina was driedovernight in a vacuum desiccator, then impregnated with the remaining 30ml of solution and dried for 5 hours in a vacuum desiccator. The 88.3 gof impregnated alumina so prepared contained 13.29 weight percent MoO₃on an ignition-loss free basis (ignition loss=38.6%).

Two catalysts, designated A and B, were prepared from this same batch ofimpregnated alumina. Catalyst A was prepared by decomposing the catalystprecursor composite in an atmosphere of hydrogen, hydrocarbon and sulfuras disclosed and claimed in U.S. Pat. No. 4,431,747, whereas Catalyst B,the catalyst of this invention, was prepared by decomposing the catalystprecursor composite in the presence of hydrogen and hydrogen sulfide.

In the preparation of catalyst A, 28.0 g (35 ml) of the impregnatedalumina was thermally decomposed in a fixed bed reactor by (1) heatingunder 500 psig of H₂ to 200° C., (2) establishing a liquid feed flow of0.825 LHSV with a blend of 5% dibenzothiophene (DBT) dissolved indecalin and a gas flow of 900 SCF/B with 100% H₂, still at 500 psig, (3)holding 4.5 hours at 200° C., and then (4) heating to 330° C. andholding for 16 hours. The reactor was cooled under hydrogen anddischarged in an inert atmosphere, yielding 19.77 g of solids material.The solids material was promoted by impregnating in an inert atmospherewith 2.54 g of cobalt nitrate, dissolved in enough acetone to give 16 mlof solution, and drying overnight in a vacuum desiccator. The finishedCatalyst A contained 3.73 weight percent CoO and 14.01 weight percentMoO₃, on an ignition-loss free basis (ignition loss=19.5%), and had 183m² /g surface area and 0.425 ml/g pore volume.

In the preparation of Catalyst B, the catalyst of this invention, 24.2 g(30 ml) of the impregnated alumina was thermally decomposed in a fixedbed reactor by (1) establishing a flow of 15.0 std liters/hr of nitrogenat room temperature and atmospheric pressure, (2) heating to 200° C.,(3) switching to a flow of 15.0 std liters/hr of 10 vol.% hydrogensulfide in hydrogen, at atmospheric pressure, (4) holding at 200° C. for2 hours, and the (5) heating to 327° C. and holding for 16 hours. Thereactor was cooled under nitrogen and discharged in an inert atmosphereyielding 17.6 g of solids material. The solids material was promoted byimpregnating in an inert atmosphere with 2.18 g of cobalt nitrate,dissolved in enough acetone to give 14 ml of solution, and dryingovernight in a vacuum desiccator. The finished Catalyst B contained 4.24weight percent CoO and 13.63 weight percent MoO₃, on an ignition-lossfree basis (ignition loss=15.8%). The catalyst also contained 2.31 wt. %carbon and 5.70 wt. % sulfur, and had 188 m² /g surface area and 0.492ml/g pore volume.

The catalytic activity of Catalyst A and B were measured in aside-by-side hydrotreating test, along with a conventional, commerciallyavailable cobalt molybdenum catalyst, designated "X". The conventionalcatalyst contained 3.22 weight percent CoO and 12.81 weight percentMoO₃, and had 239 m² /g surface area and 0.471 ml/g pore volume. Thetest feedstock was a Baton Rouge light catalytic cycle oil (LCCO)designated FS-4754. Inspections on this feedstock are given in Table I.

                  TABLE I                                                         ______________________________________                                        Feedstock Inspections                                                                      Feedstock No.                                                                 FS-4574 FS-4754   FS-5171                                        ______________________________________                                        API Gravity    25.1      19.3      15.6                                       Sulfur, Wt. %  1.41      1.48      1.74                                       Nitrogen, ppm  228       327       274                                        Bromine No. mg/cc                                                                            6.3       4.4       5.6                                        Carbon, wt. %  87.36     88.51     88.81                                      Hydrogen, wt. %                                                                              11.23     9.98      9.42                                       FIA Aromatics  49.0      71.0                                                 Olefins        8.5       2.5                                                  Saturates      42.5      27.0                                                 Distillation                                                                   5%            448       473       465                                        50%            541       538       516                                        95%            671       634       642                                        ______________________________________                                    

Hydrotreating conditions were 330° C., 750 psig, and 1200 SCF/B of 100%H₂ with space velocities ranging from 0.5 to 2.0 V/H/V. Activity wasmeasured as the reciprocal space velocity required to reach a givendesulfurization or denitrogenation target, and relative activitiesremained constant over the entire range of 85-97% HDS and 62-98% HDN.Per gram of molybdenum, Catalyst A had 1.47 times the desulfurizationactivity and 1.81 times the denitrogenation activity of the conventionalcatalyst. Catalyst B had only 0.79 times the desulfurization activity ofthe conventional catalyst, but had 1.70 times the denitrogenationactivity. Catalyst B, has a much higher HDN/HDS selectivity than eitherthe commercial catalyst or Catalyst A, albeit. Catalyst A has muchhigher HDS activity than either catalyst B or the conventional catalyst.

These data clearly demonstrate the advantage of carrying out thedecomposition of the catalyst precursor composite in the presence ofhydrogen sulfide and hydrogen when high HDN/HDS selectivity is desired.It also demonstrates the difference between the catalysts of thisinvention and otherwise similar but unsupported catalysts of Pecoraroand Chianelli, or Chianelli and Pecoraro, supra, because of theselectivity in the preparation of the catalysts.

EXAMPLE 2

A solution was prepared by dissolving 14.50 g of an ethylenediamine saltof thiomolybdic acid in 43.5 ml of butylamine. Analysis of the saltindicated that only one nitrogen of each ethylenediamine moiety wasprotonated, and that the salt had the approximate formula (H₂ NC₂ H₄NH₃)₂ (MoO₀.5 S₃.5). This solution was used to impregnate 46.9 g of thesame 14/35 mesh gamma alumina used in Example 1. The alumina was driedovernight in a vacuum desiccator. The impregnated alumina was thentreated to decompose the thiomolybdate salt by heating at a rate of4°/min to a final temperature of 327° C., in a fixed bed reactor with aflow of 10% H₂ S/90% hydrogen, at a flow rate of 500 volumes of gas pervolume of catalyst per hour. The reactor was cooled under nitrogen andthe product discharged in an inert atmosphere. Of the 52.0 g of materialso prepared, 50.0 g of the solids material was then impregnated with asolution of 7.04 g of cobalt nitrate, dissolved in enough acetone togive incipient wetness, and dried overnight in a vacuum desiccator. Thiscatalyst, designated C, contained 3.49 weight percent CoO and 11.04weight percent MoO₃, on a ignition-loss free bais (ignitionloss=11.21%). It also contained 3.00 wt. % carbon and 4.71 wt. % sulfur.

The catalytic activity of Catalyst C was measured in a side-by-sidecomparison with the same conventional catalyst, Catalyst X, described inExample 1, treating the feedstock FS-4574 (Table I) at 330° C., 520psig, and 600 SCF/B. Catalyst C, like Catalyst B, showed a very highHDN/HDS selectivity, with 0.69 times the desulfurization activity of theconventional catalyst, and 1.27 times the denitrogenation activity.

EXAMPLE 3

A tridodecylamine salt of thiomolybdic acid was made in the followingmanner. A portion, 1.88 g, of commercial "Molybdic Acid" (Mostly anammonium molybdate, containing 85% MoO₃) was suspended in 150 ml ofwater, which was saturated with hydrogen sulfide by sparging with 100%H₂ S for ten minutes. The solution was extracted vigorously in aseparatory funnel with a second solution of 10.4 g of tridodecylamine in150 ml of toluene. The solution was then re-saturated and re-extractedwith toluene in the same manner three additional times. The tolueneextract was dried overnight in a vacuum oven at 60° C., washed 3 timeswith hexane, and dried for 4 more hours, yielding about 5.5 g oftridodecylamine thiomolybdate, a brown tarry material. Chemical analysesindicated that the brown tarry material had the approximate formula((C₁₂ H₂₅)₃ NH)(NH₄)(MoO₁.5 S₂.5)).

A solution of 11.1 g of this material in 150 ml of toluene was slurriedwith a 16.7 g portion of the same calcined 14/35 mesh gamma aluminadescribed in Example 1. The mixture was stirred under a nitrogen blanketwhile the toluene slowly evaporated. The large, bulky tridodecylaminethiomolybdate molecules were absorbed by the alumina, diffusing into thealumina slowly, the sample having had to be re-wetted with toluene andre-dried several times, until a piece of alumina, broken open, revealeda uniform brown color across its interior. This procedure yielded 22.6 gof material which contained 7.01 wt. % MoO₃, on an ignition-loss freebasis (ignition loss=19.5%).

This material was thermally decomposed in 10% H₂ S/90% H₂, discharged inan inert atmosphere, and promoted with cobalt nitrate in acetonesolution in the same manner described in Example 2, except that themaximum decomposition temperature was 370° C. The finished catalyst,designated D, contained 2.78 wt. % CoO and 8.25 wt. % MoO₃, on anignition-loss free basis (ignition loss=15.2%). The finished Catalyst Dalso contained 8.07 wt. % carbon and 2.56 wt. % sulfur, and had 162 m²/g surface area and 0.426 ml/g pore volume.

The catalytic activity of Catalyst D was measured in the same manner asCatalyst C, at the same conditions. Per gram of molybdenum, Catalyst Dhad 1.13 times the desulfurization activity of the conventional CatalystX and 1.27 times its denitrogenation activity. This catalyst has asignificantly higher HDN activity than the conventional Co/Mo catalyst,and showed some improvement in HDN/HDS selectivity.

EXAMPLE 4

A solution was prepared by dissolving 12.32 g of hexanediaminethiomolybdate in 30 ml of butylamine. Analysis of the salt showed that,unlike the ethylenediamine salt, both nitrogens in each hexanediaminemoiety were protonated. The salt had the approximate formula (H₃ NC₆ H₁₂NH₃)(MoO₀.1 S₃.9). This solution was used to impregnate 33.4 g of thesame calcined 14/35 mesh gamma alumina used in Example 1. The aluminawas dried overnight at 60° C. in a stream of flowing nitrogen at reducedpressure, about 3-5 psia. The alumina was then treated to decompose thethiomolybdate in the same manner described in Example 2.

Of the approximately 37 g of solids material so prepared, 17.0 g wasimpregnated with a solution of 2.47 g of cobalt nitrate dissolved in32.3 ml of acetone, and dried overnight in a vacuum desiccator. Thiscatalyst, designated E, contained 3.65 wt. % CoO and 12.9 wt. % MoO₃, onan ignition-loss free basis (ignition loss=18.6%). The catalyst alsocontained 2.97 wt. % carbon and 4.61 sulfur, and had 186 m² g surfacearea and 0.507 ml/g pore volume.

The catalyst activity of Catalyst E was measured by hydrotreating feedFS-4574 (Table I) at 330° C., 750 psig, and 1200 SCF/B hydrogen.Catalyst E was compared to a particularly promising conventionalcatalyst designated Y, which contained 4.50 wt. % CoO, 19.5 wt. % MoO₃,and 3.25 wt. % phosphorus. Catalyst Y is unusually active fordenitrogenation, this being believed due to the presence of thephosphorus. However, based on effectiveness per gram of molybdenum,Catalyst E had 0.92 times the desulfurization activity of Catalyst Y and1.14 times its denitrogenation activity. Even in this difficultcomparison, Catalyst E showed an unusually high HDN/HDS selectivity.

EXAMPLE 5

In this example, the promoter was put onto the alumina before the aminethiomolybdate compound.

A solution of 5.34 g of cobalt nitrate dissolved in 35.9 ml of water wasused to impregnate 33.4 g of the same calcined 14/35 mesh gamma aluminadescribed in Example 1. The sample was allowed to stand covered at roomtemperature overnight, was dried for 6 hours at 120° C., and then wascalcined overnight at 540° C. The specimen was impregnated a second timewith a solution of 12.4 g of hexanediamine thiomolybdate dissolved in 35ml of butylamine. Analysis of this batch of hexanediamine thiomolybdateindicated that the specimen was fully sulfided and had the approximateformula (H₃ NC₆ H₁₂ NH₃)(MoS₄).

The sample was dried overnight in a vacuum desiccator. The specimen wasthen treated to decompose the thiomolybdate by heating at a rate of4°/min to a final temperature of 327° C., in a fixed bed reactor with aflow of 10% H₂ S/90% hydrogen, at a flow rate of 500 volumes of gas pervolume of catalyst per hour. The reactor was cooled under nitrogen andthe product discharged in an inert atmosphere to give Catalyst F.

The nominal metals contents of Catalyst F, i.e., metals content based onrecipe rather than direct analysis, are 3.4 wt. % CoO and 13.0 wt. %MoO₃, on an ignition-loss free basis. The ignition loss was measured,and was 16.6 wt. %. The catalyst also contained 4.01 wt. % carbon and6.83 wt. % sulfur.

The catalytic activity of Catalyst F was measured in a run identical tothat conducted with Catalyst E, and compared against the samephosphorous-containing conventional Catalyst Y. Putting on the promoterbefore the thiomolybdate via-a-vis putting the thiomolybdate on thesupport before the promotor it was shown had little effect, in changingcatalytic activity. Per gram of molybodenum, Catalyst F had 0.98 timesthe desulfurization activity of Catalyst Y, and 1.15 times itsdenitrogenation activity.

EXAMPLE 6

Examples 4 and 5 were repeated, except that this instance the promoterwas impregnated after the amine thiomolybdate was put onto the alumina,but before the thiomolybdate was thermally decomposed. This slightchange in the method of preparing the catalyst, it will be observed, hada major effect on catalytic selectivity.

A solution was prepared by dissolving 50.0 g of hexanediaminethiomolybdate in 165 ml of butylamine. Analysis of this particular batchof hexanediamine thiomolybdate indicated that it, like the batch used inExample 5, was fully sulfided and had the approximate formula (H₃ NC₆H₁₂ NH₃)(MoS₄). The solution was filtered, and 95 ml of the filtrate wasused to impregnate 90.2 g of the calcined 14/35 mesh gamma alumina. Thisalumina was very similar to the alumina described in Example 1, and had255 m² /g surface area and 0.684 ml/g pore volume. The alumina was driedovernight at 45° C. under flowing nitrogen at reduced pressure, about3-5 psia, then impregnated with the remaining butylamine solution andagain dried overnight at the same conditions.

The 146.9 g of solids material so prepared was impregnated with a secondsolution, made by dissolving 15.8 g of cobalt nitrate in enough acetoneto give 45 ml of solution. The impregnated alumina was again driedovernight at the same conditions to give 161.2 g of catalyst, designatedG. The finished Catalyst G contained 3.83 wt. % CoO and 17.4 wt. % MoO₃,on an ignition-loss free basis (ignition loss=30.09%). Catalyst G alsocontained 11.37 wt. % carbon and 11.18 wt. % sulfur, and had 40.6 m² /gsurface area and 0.158 ml/g pore volume.

The catalyst precursor was thermally decomposed in the same fixed bedreactor in which the activity test was carried out. Prior to theactivity test, a flow of 500 V/H/V of 10% H₂ S in hydrogen wasestablished, at atmospheric pressure and room temperature. Thetemperature was increased to 200° C. at about 1.5°/min, held at 200° C.for 2 hours, then increased to 330° C. at about 1°/min and held at 330°C. for 16 hours. The reactor was then cooled to 325° C. and pressurizedwith hydrogen. Treat gas and liquid feed flows to the reactor wereestablished. Thest conditions were 325° C., 750 psig, and 1500 SCF/B, tohydrotreat the FS-4754 feedstock. Because of the higher metals contentof Catalyst G, the comparison was made against a third conventionalcatalyst, designated Z, which contained 4.08 wt. % CoO and 15.86 wt. %MoO₃. Catalyst Z had 235 m² /g surface area and 0.480 ml/g pore volume.Catalyst Z typically shows somewhat higher activity, but very similarselectivity patterns, as the first conventional catalyst, X.

In this test, Catalyst G had 0.83 times the denitrogenation activity ofCatalyst Z. The overall activity is somewhat low, but the HDN/HDSselectivity is more than 9 times that of a conventional hydrotreatingcatalyst. The desulfurization activity is only 0.09 times that of aconventional hydrotreating catalyst.

EXAMPLE 7

Conventional sulfided molydenum hydrotreating catalysts are oftenpromoted with nickel instead of cobalt, and this frequently increasesthe HDN/HDS selectivity. In this example, a direct comparison is made ofthe effects of nickel vs. cobalt promotion for the catalysts of thisinvention. It is shown that the catalysts of this invention have highselectivity for nitrogen removal, not only by comparison to sulfurremoval, but also by comparison to hydrogen consumption.

A solution was prepared by dissolving 72.0 g of tetrabutylammoniumthiomolybdate in enough methanol to give 180 ml of solution. Analysis ofthe tetrabutylammonium thiomolybdate indicated that it had theapproximate formula ((C₄ H₉)₄ N)₂ (MoO₀.5 S₃.5). This solution was usedto impregnate to incipient wetness 167.0 g of the same 14/35 meshcalcined gamma alumina used in Example 1. The alumina was dried for 3days in a vacuum desiccator. The impregnated alumina was thenimpregnated with a second solution of 56.0 g of tetrabutylammoniumthiomolybdate, having essentially the same analyses, dissolved in enoughmethanol to give 140 ml of solution, and dried in a vacuum desiccatorovernight. The 295.8 g of impregnated alumina so prepared contained 13.9g weight percent MoO₃, on an ignition-loss free basis (ignitionloss=36.43%).

Four equal portions of this impregnated alumina, with a combined weightof 197.0 g (240 ml), were thermally decomposed in fixed bed reactors atthe same conditions described in Example 6. The portions of alumina weredischarged in an inert atmosphere.

To make Catalyst H, three of these portions were recombined, yielding94.85 g of solids material. This combined portion was impregnated with13.56 g of cobalt nitrate dissolved in enough acetone to give 96 ml ofsolution, and dried for 4 days in a vacuum desiccator. The finishedCatalyst H weighed 108.89 g, and contained 3.35 wt. % CoO and 13.52 wt.% MoO₃, on an ignition-loss free basis (ignition loss=13.93%). CatalystH also contained 2.21 wt. % carbon and 5.12 wt. % sulfur, and had 189 m²/g surface area and 0.450 ml/g pore volume.

To make Catalyst J, the remaining portion of decomposed aluminasupported thiomolybdate, weighing 31.52 g was impregnated with 4.55 g ofnickel nitrate dissolved in enough acetone to give 32 ml of solution.The impregnated portion of alumina dried for 4 days in a vacuumdesiccator. The finished Catalyst J weighed 36.00 g, and contained 3.70wt. % NiO (based on recipe, not analysis) and 13.12 wt. % MoO₃, on anignition-loss free basis (ignition loss=12.04%). The catalyst alsocontained 2.48 wt. % carbon and 4.94 wt. % sulfur. It had 186 m² /gsurface area and 0.432 ml/g pore volume.

The catalysts activities were determined in side-by-side tests, alongwith both conventional Catalyst X and Catalyst Z. Per gram ofmolybdenum, conventional Catalyst X and Catalyst Z gave almost identicalactivities, both for desulfurization and for denitrogenation. This wasexpected because the only major difference between them is a higheroverall metal level on Catalyst Z, which is compensated for byexpressing the activities on a per gram of molybdenum basis. On theother hand, Catalyst H had only 0.78 times the desulfurization activityof the conventional catalysts, but 1.26 times the denitrogenationactivity of the conventional catalysts. Catalyst J had 0.35 times thedesulfurization activity of the conventional catalysts and 1.88 timesthe denitrogenation activity. Thus, the tendency for nickel promotedcatalysts to be selective for HDN over HDS is manifested in thecatalysts of this invention.

The hydrogen contents of the feed, liquid product, and off-gas from thisparticular activity test were very carefully measured, and the chemicalhydrogen consumption of each catalyst was determined. Chemical hydrogenconsumption is usually very closely correlated with nitrogen removal,since carbon-nitrogen bonds are stabilized by adjacent aromatic ringstructures and are usually broken only after such aromatic rings havebeen hydrogenated. However, the relationship is more favorable for thecatalysts of this invention than for conventional catalysts.

In hydrotreating a light cat cycle oil from a Baton Rouge refinery(FS-4754) to provide an 80 ppm nitrogen level in the liquid product,Catalyst H and J required only 625 SCF/B hydrogen consumption, whileboth conventional catalysts required 750 SCF/B. Hydrotreating to 20 ppmnitrogen, the chemical hydrogen consumptions were 725 and 850 SCF/B,respectively. Indeed, as shown in the attached FIGURE, at any givennitrogen level in the product both Catalyst H and J required the samehydrogen consumption, while both conventional catalysts required about125 SCF/B more hydrogen. The accuracy of determination of the hydrogenconsumption values is about 30 SCF/B. Thus, the catalyst of thisinvention can hydrotreat a given hydrocarbon feed to a given nitrogentarget level with about a 125 SCF/B savings in hydrogen consumption,which represents a considerable cost savings. This reduction in hydrogenconsumption is quite unexpected. The fact that both cobalt and nickelpromoted Catalysts H and J show this advantage is quite significant, anddemonstrates that it is a basic characteristic of supported aminethiomolybdate catalysts decomposed in a reducing, sulfiding environment.

It is apparent that various modifications and changes can be madewithout departing the spirit and scope of the present invention.

Having described the invention, what is claimed is:
 1. A process forhydrotreating a hydrocarbon feed which comprises contacting said feed,in the presence of hydrogen, at hydrotreating conditions with asupported carbon-containing molybdenum sulfide and tungsten sulfidehydrotreating catalysts formed by the steps comprisingcompositing apreselected quantity of a porous, refractory inorganic oxide with a saltcharacterized by the formula

    B.sub.x [MO.sub.y S.sub.4-y ]

where B is an organo or hydrocarbyl substituted diammonium ion, anorgano or hydrocarbyl substituted ammonium ion or quaternary ammoniumion, or an ionic form of a cyclic amine containing one or more basic Natoms, x is 1 where B is an organo or hydrocarbyl substituted diammoniumion, or 2 where B is an organo or hydrocarbyl substituted ammonium orquaternary ammonium ion or an ionic form of a cyclic amine containingone or more basic N atoms, M is molybdenum or tungsten, and y is 0, or afraction or whole number ranging up to 3, andheat decomposing the saltof said catalyst precursor composite in the presence of a gaseousadmixture consisting essentially of hydrogen and hydrogen sulfide toform said supported carbon-containing molybdenum sulfide or tungstensulfide hydrotreating catalyst.
 2. The process of claim 1 wherein thesupported carbon-containing molybdenum or tungsten sulfide hydrotreatingcatalyst precursor composite, prior to decomposition of the salt,contains from about 5 percent to about 30 percent of the salt,calculated as MoO₃ or WO₃ on an ignition loss free basis.
 3. The processof claim 2 wherein the catalyst precursor composite is heated attemperatures ranging from about 150° C. to about 400° C. to heatdecompose the salt of said composite.
 4. The process of claim 3 whereinthe decomposition temperature ranges from about 200° C. to about 370° C.5. The process of claim 2 wherein the decomposition temperature rangesfrom about 150° C. to about 400° C., and the salt impregnated catalystprecursor composite is contacted with the gaseous admixture containinghydrogen sulfide and hydrogen at a flow rate ranging from about 50 toabout 5000 V/H/V, and at pressures ranging from about 0 to about 2000psig.
 6. The process of claim 5 wherein the flow rate of the gaseousadmixture containing hydrogen sulfide and hydrogen ranges from about 100to about 1000 V/H/V, the pressure ranges from about 0 to about 200 psig,and the concentration of hydrogen sulfide within the gaseous admixtureranges from about 0.5 percent to about 50 percent.
 7. The process ofclaim 2 wherein the porous, refractory inorganic oxide is alumina. 8.The process of claim 2 wherein the porous, refractory inorganic oxide isparticulate alumina, the salt is dissolved in a solvent, and theparticulate alumina and salt solution are contacted together and theparticulate alumina impregnated with the salt solution, the impregnatedalumina is dried to remove the solvent, and the dry, salt-impregnatedalumina heated to a temperature sufficient to decompose the salt andform said supported carbon-containing molybdenum sulfide or tungstensulfide hydrotreating catalysts.
 9. The process of claim 2 wherein, inthe salt characterized by the formula B_(x) [MO_(y) S_(4-y) ], M ismolybdenum and y ranges from 0 to 0.5.
 10. The process of claim 2wherein a group VIII metal or admixture of said metals, exclusive ofsaid metal added by incorporation of said heat decomposablethiomolybdate or thiotungstate salt, is composited with said supportedcarbon-containing molybdenum sulfide or tungsten sulfide hydrotreatingcatalyst.